An analysis is developed of the documentation stored in the Archive of Simancas which contains the judicial actions against smuggling carried out by the Spanish Monarchy as part of its active policy of trade embargoes. In a first approach to the issue, the commercialization of the luxury products of the capital between 1635 and 1673 has been studied. Besides a description of the administrative and judicial network, the repressive mechanisms devoted to the control of illegal trade and the typology of the products, geographical origin and distribution channels, some indications are presented about the main ways of transgression, corruption and the limits in the application of the embargoes. The use of the Hispanic markets as a war weapon did not permit the total closure to the entry of products from the enemy but it seriously hindered the free trade of goods and it gave a remarkable advantage to those traders who enjoyed the protection of the Crown. The article tries also to give some indications about the nature of the sumptuary laws, conceived more as a mechanism of social constraint in order to give a privileged access to the aristocracy into the luxury products markets, rather than a protectionist measure. This ostentation and growing consumption of luxury goods, given the absence of a productive base, were an additional component in the process of the Castilian economy becoming peripheral, and at the same time they reinforced its dependency with respect to the community of foreign merchants, who were responsible for distributing the agrarian surpluses of the nobility and for lending to the Crown.